(i) Technical Field
The invention relates to a transfer roller, a process cartridge, and an image forming apparatus.
(ii) Related Art
An image forming apparatus using an electrophotographic system forms charges on a surface of an image carrier such as a photoreceptor by using an exposure device, forms an electrostatic latent image by using a laser beam modulated with an image signal, then develops the electrostatic latent image with charged toners to form a visualized toner image, and directly transfers the toner image to a recording medium or transfer the toner image to the recording medium via an intermediate transfer body.
For example, in a case of an intermediate transfer method, the toner image formed on the surface of the image carrier is primarily transferred to a surface (an outer circumferential surface) of an intermediate transfer belt in an electrostatic manner, then is secondarily transferred to the recording medium such as a recording sheet in an electrostatic manner, and then is heated and pressurized in a fixing device so as to be fixed on the recording medium.
As a transfer roller for transferring the toner image on the image carrier to the recording medium or transfers the toner image to the intermediate transfer belt, or as a transfer roller for transferring the toner image on the intermediate transfer belt to the recording medium, various conductive rollers have been developed.